Nuclear pollution, also known as radioactive contamination, is the unintentional or undesirable presence of radioactive chemicals on surfaces or inside of solids, liquids, or gases (including the human body). Nuclear pollution is the term for radiation and radioactive particle pollution of the atmosphere. The radioactive decay of the contaminants, which results in the production of ionizing radiation (namely alpha, beta, and gamma rays) and free neutrons, makes such contamination dangerous.

The concentration of the pollutants, the energy of the radiation being produced, the kind of radiation, and the closeness of the contamination to body organs all affect how dangerous the situation is. The phrases "radiation" and "contamination" should not be used interchangeably; it is crucial to understand that contamination creates the radiation hazard. The generation of radioactive wastes such spent (used) reactor fuel, uranium mill tailings, and other radioactive wastes is a significant environmental hazard associated with nuclear power. For millions of years, these substances may continue to be radioactive and hazardous to human health. To protect public health and the environment, specific rules regarding the management, transportation, storage, and disposal of radioactive wastes must be followed.

When radioactive materials are present or are deposited in the environment, especially when this is unintentional and poses a risk to the ecosystem owing to radioactive decay, radioactive contamination develops. The radioactive materials' ability to emit dangerous ionizing radiation (radioactive decay) like beta or alpha particles, gamma rays, or neurons into the environment where they are found is what causes the devastation. By raising these materials from the earth's surface, mining speeds up natural geological processes. The minerals thorium, plutonium, radon, potassium, carbon, and phosphorus also contain traces of radiation. The concentration of the pollutants, the energy of the radiation being produced, the kind of radiation, and the closeness of the contamination to body organs all affect how dangerous the situation is. The phrases "radiation" and "contamination" should not be used interchangeably; it is crucial to understand that contamination creates the radiation hazard. The condition most commonly brought on by radiation is cancer. It has grown over time and now represents a serious threat to world health. Leukemia, anemia, hemorrhage, a shorter life expectancy that causes premature aging and fatalities, as well as other conditions like cardiovascular issues, are among the others. For instance, radiation in the bone marrow results in leukemia.